OPI Nature Strong in Onyx Skies is an opaque black crème nail lacquer from OPI's natural-origin line, formulated with up to 75% of its classic-lacquer ingredients derived from plant and mineral sources such as sugar cane, wheat, corn, and clay instead of the usual petrochemical feedstocks. It's a 9-free formula, made without formaldehyde, formaldehyde resin, toluene, xylene, DBP, camphor, parabens, ethyl tosylamide, and triphenyl phosphate, and it's vegan and Vegan Society-certified.
Unlike most OPI lacquers, Nature Strong doesn't require a base coat, though pairing it with the separately sold Nature Strong Top Coat extends wear. Two coats of color alone are rated for up to 7 days of wear and shine. The bottle and cap are made with 20% post-consumer recycled plastic.
Usage: prep and clean the natural nail, shake the bottle well, then apply two thin coats, capping the free edge of each. Finish with Nature Strong Top Coat if desired for extra shine and durability.